Bundesliga champions Bayern Munich head to RB Leipzig on Matchday 4 for their toughest test of the 2021/22 campaign yet - bundesliga.com weighs up the title contenders ahead of Saturday's top-of-the-bill encounter.
Leipzig have had a mixed start under their new American boss. "We showed a great reaction after last week's defeat to Mainz and took the reins from the start," said Marsch as his side roared back from their surprise season-opening loss at Mainz by smashing four past Stuttgart at home on Matchday 2. "We were aggressive and staged a very good performance today."
Watch: Robert Lewandowski hits a hat-trick as Bayern rout Hertha
That run started under Nagelsmann, and his Bayern dug-out debut at Borussia Mönchengladbach ended with just a point. However, his side have since clicked formidably into gear, beating both Cologne and Hertha Berlin and scoring eight goals in 180 minutes.
"We put on our best performance of the season today," said Nagelsmann after dismantling Hertha 5-0. That doesn't bode well for his former club.
With Leipzig only founded late in the first decade of the millennium and earning top-flight status in 2016/17, there have only been 10 Bundesliga meetings between the duo.
Bayern have the upper hand with five wins, and they recorded only their second win at the Red Bull Arena last season thanks to Leon Goretzka's first-half goal.
The four encounters prior to that ended in draws, an indication of just how much Leipzig have closed the gap between themselves and the record Bundesliga champions.
Leipzig have beaten Bayern in the league just once: a 2-1 home triumph on Matchday 27 of the 2017/18 season when former Bayern reserve team player Ralph Hasenhüttl was in charge with Naby Keita and Timo Werner getting the goals after Sandro Wagner had given the visitors an early lead.
If the pair serve up anything like the spectacle they delivered with Bayern's 5-4 win in Leipzig on Matchday 33 of the 2016/17 campaign - a game in which Bayern came from 4-2 down in the closing six minutes - then no one will be complaining.
Watch: The story of RB Leipzig 4-5 Bayern Munich
"These are the games you dream of playing against some of the best teams in the world," said Leipzig's USMNT midfielder Tyler Adams.
"It's a game we want to win, we know it's going to be obviously a difficult match, Bayern is no easy game ever but we're excited for these games."
Leipzig have a 6'3"-sized problem: Manuel Neuer, one of the greatest goalkeepers the game has ever seen.
Recovered from an ankle injury sustained in the DFL Super Cup, Neuer continues to be a nightmare for opposing teams who find it almost impossible to get the ball into the Bayern net.
With his club's win over Hertha, the 35-year-old racked up his 205th clean sheet in the Bundesliga, passing Bayern and Germany predecessor Oliver Kahn to claim the German top-flight record. While Kahn took 557 games, Neuer has played just 441 matches.
How can Leipzig counterpart Peter Gulasci match up to that? Simply, he can't. But that's not to say Bayern will find it easy to pass the Hungary international.
Gulasci has kept two clean sheets in his last five games against Bayern, while both he and Neuer conceded three in the duo's gripping six-goal encounter on Matchday 10 last season.
One of the reasons for Leipzig's stumbling start is their backline. Of the four-man defence that started against Wolfsburg last time out, only two were even at the club last season - Lukas Klostermann and Willi Orban - with Josko Gvardiol and Mohamed Simakan both coming in over the summer.
The departures of Dayot Upamecano - to Bayern - and Ibrahima Konaté, and injuries to Angelino and Marcel Halstenberg have meant Marsch has had to tweak his defence more than he surely would have liked.
Watch: Why Dayot Upamecano is the perfect signing for Bayern Munich
Pavard's problems have allowed academy prospect Josip Stanisic to stake his claim for a first-team place with Nagelsmann - bar a first-half experiment with a back three at home to Cologne - opting for the flat back four that has been the cornerstone of Bayern's nine successive title wins.
There is no doubt Marcel Sabitzer's departure from Leipzig for Bayern weakened the former and strengthened the latter. The Austria international has been stunning since getting a first taste of the Bundesliga along with his former club in 2016.
What is crazy about Sabitzer's signing is that - despite Nagelsmann clearly being a fan - he is not likely to be first-choice unless the Bayern boss adopts a three-man midfield. With FIFA World Cup winner Corentin Tolisso - injured right now - and young duo Michael Cuisance and Marc Roca waiting in the wings, Nagelsmann is spoilt for choice.
If he opts for a midfield two, however, then Sabitzer will have to bide his time with Goretzka and Joshua Kimmich surely on the Red Bull Arena pitch at kick-off.
While Goretzka will see Sabitzer challenge for his place, Kimmich - recently promoted to Germany captain in Neuer's absence - will underpin the middle of the pitch for Bayern for years to come, particularly after signing a new deal through to 2025. He will not only provide the link between defence and attack for the visitors, but will be tasked with keeping a tight leash on Leipzig's most creative players like Dani Olmo and Emil Forsberg.
Adams is just as important for Leipzig after seemingly being installed definitively as a Sechser - a Six, a holding midfielder - in front of Marsch's defence.
Watch: Dominik Szoboszlai doubles up as Leipzig dispose of Stuttgart
With Dominik Szoboszlai, who scored twice against Stuttgart, and Christopher Nkunku more attack- than defence-minded, Adams has a crucial role in picking off opposition attacks, and will likely have to deal with Goretzka's forward bursts or Thomas Müller - if he is fit - dropping into space on the edge of the Leipzig penalty area.
Marsch called for, "Total passion, power, energy, positivity…" from his squad when he took charge this summer. He'll get all of that - and will need it - from Adams.
"I asked him at half-time whether he wasn't fit or if he'd gone to the next level, because for the first time he left the ball in the penalty area to someone in a better position." Müller loves a joke, and the Bayern man's questioning of Robert Lewandowski was surely in jest.
Lewandowski's dummy that allowed Müller to open the rout against Hertha was not all that unusual, and given the Poland international finished the match with three goals, he could afford to be selfless.
The 33-year-old broke the seemingly unbreakable Bundesliga season scoring record of Gerd Müller with an incredible 41 strikes in 29 outings, and he's already got five in three this term, as many as he had at the same stage in 2020/21.
"Of course I'm always hungry, but especially physically I feel very good, probably better than three years ago," said Lewandowski after the Hertha game and having broken another Müller mark by netting in his 16th competitive match for Bayern, and his 13th in the Bundesliga.
"I'm just focused on my task in every game, I don't worry about records."
One record Lewandowski won't be too keen to be reminded of is his against Leipzig: after four goals in his first three meetings with Die Roten Bullen, he's scored just one in his last six, somehow even failing to find the net in last season's six-goal thriller before sitting out the return fixture through injury.
Bayern do have goals from other sources though with Serge Gnabry, who got two in the 3-2 win over Cologne, and Jamal Musiala, who opened his 2021/22 account against Hertha, while Müller got two in that six-goal thriller at the Allianz Arena last December.
Andre Silva scored an impressive 28 times in 32 league games for Eintracht Frankfurt last season, as Lewandowski's nearest challenger, and the 25-year-old netted his first goal since his summer move to Leipzig in the Matchday 2 win over Stuttgart, and will be the hosts' primary threat.
"All of my strikers need to know that it’s not just about scoring goals but that up front we need a lot of power and mentality in our counter-pressing so that we can put opposition defenders under pressure," he explained.
Watch: Andre Silva's Bundesliga Mixtape!
If Leipzig are to inflict a first defeat of the season on Bayern - and make a statement of intent about ending the Bavarians' nine-season grip on the Meisterschale - pressing and precision finishing will be required.
Both men in the dug-out have been part of the Red Bull system, but does it give anyone an advantage in their first head-to-head meeting in Germany?
"No, I don't think it makes it harder to beat Bayern," said Adams when asked if Nagelsmann's familiarity with the Leipzig squad will handicap the hosts.
"I think that Julian is an amazing coach. Tactically and personally, he helped me develop so much. Now playing against him will be a little bit weird and different, but that's just football."
It is not as if Marsch will not be familiar with Bayern or how they play, even if Nagelsmann may be tempted to surprise his former colleague with a tactical tweak.
"I think the coaching styles are a little bit different tactically - it's hard to pick one little thing or two little things that are so different. But we're a different team than last year," said Adams. "We kept some of the amazing things that Julian did in the structure of the team but Jesse brings his new fresh ideas and different types of energy and I think that will help us."